Half to peter collamore



i (No Model.) 4 S 1 J. G. PENNYGUIGK.

I 'TILE FOR ILLUMINATING PURPOSES. .No. 247,996. 'Patentedflot. 4,1881

WITNESSES: INVENTOR:

. UNITED STATES PATENT OFFICE- JAMES G. PENNYOUIGK, ()F BOSTON,MASSACHUSETTS, ASSIGNOR OF ONE- HALF TO PETER'OOLLAMORE, OF SAME PLACE.

TILE FOR ILLUMINATING PURPOSES.

SPECIFICATION forming part "of Letters Patent No. 247,996, dated October4, 1881.

Application filed June 13, 1881.

To all whom it may concern:

Be it knownthat I, JAMEs G. PENNYCUICK, ofBoston, Suffolk county,Massachusetts, have invented a new and useful Improvement in ,5 Tilesfor Illuminating Purposes, of which the following is a specification.

' My improvements relate to theilluminatingtiles used in pavements,vault-covers, and in other situations.

Lenses have heretofore been made for such tiles in simple flat form, andalso as-prisms, with the object to reflect or scatter the light to thegreatest possible extent; but heretofore such results have not beenobtained on account of the limited area of reflecting-surface and theabsorption of the light by the prism.

The object of my invention is to increase the quantity of light and toproject the same over a wide extent of surface, so that theillumination, instead of being limited to the direct light due to thesuperficial area of the tiling minus the loss by refraction, isincreased and diffused to the greatest possible extent.

My invention consists, first, in illuminatinglens of semi-prismform andhaving an extensive reflecting-surface in comparison to the quantity ofmaterial used; and, second, in the combination, with such lens, of metalspurs for preventing slipping and to prevent abrasion of the exposedsurface, as hereinafter described and claimed.

1n the accompanying drawings, Figure l is a longitudinal section of theimproved lens or semi-prism as fitted in a frame for use. Fig. 5 2 is atop view of the lens; and Figs. 3 and at are elevations, showingmodifications in the forms.

Similar letters of reference indicate corresponding parts.

A in Fig. l is a portion of a vault or pavementplate or framefltted withthe illuminatinglens B, which is preferably made of crown-glass. Thelens or semi-prism B is formed with a flanged top portion, a, which maybe of circu- 5 lar or angular form to fit a flanged opening in the plateA, whereby the lens is retained, and suitable packing material will beused to render the joint water-tight. The upper surface is preferablyformed, as shown most clearly in Fig. 2, raised at the center and withradiating (No model.)

grooves having beveled sides, so as to increase the extent of surface.The beveled surfaces being depressed, they are also protected fromabrasion. The upper surface may, however, be of simple conical form, asin Fig. 4; or in certain situations a plain flat surface, as in Fig. 3,may be used.

At the center of the upper surface a metal spur or spurs, c, is fittedin a recess in the lens, so as to project slightly and protect the sur-6c face. The frame A is formed, as shown, with knobs orprojectionsdbetween the tiles, so that the feet ofpersons walking overthe frame shall be kept entirely off thelens, and slipping thusprevented. From the head a the lens projects 6 5 downward in form ofatongue, h. This downwardly-extending portion may be described generallyas a semi-prism having an inclined flat reflecting-surface, e, and aninclined back face,f, that may be flat or nearly flat, convex, orconcave. The angle of the surface 0 will vary according to location, andis of the first importance. For a pavement-light, as shown, it should beslightly less than forty-five degrees to the plane ofl'rame A.Itislengthened by the inclination of the back surface, f, from the heada to the lower point, so that while only a limited amount of material isused, thereby saving weight and loss of light, an extensivereflecting-surface is obtained at the 8 proper angle.

The frame A can be placed in a horizontal, vertical, or inclinedposition, the angle of the semi-prism being varied to correspond. Thelens shown in Fig. 3 is adapted for a verti- 5 cal frame asa substitutefor a window. The tiles can also be formed in clusters instead of singlyfor certain locations.

With this illuminating-tiling the light is magnified greatly in strengthand a soft diffu- 9 sive light obtained which is superior to directsunlight for most purposes. The tilingis especially useful where only anindirect light is to be had, as such light is concentrated andstrengthened instead of being partly cut off. They may also be used withgreat advantage for gas-chandeliers and in connection with the electriclight. In all cases the reflecting-surfaces glow withasilver-whitelightmost agreeable to the eyes.

For particular situations the lenses may be plain or corrugated, wavedor angular on the reflecting-surface, and they maybe coated withsterling silver or other reflecting substance.

5 I am aware that pyramidal lenses have been used; but they concentratethe light too much and diffuseit too little. They decrease instead ofincreasing the quantity of light admitted, while mine greatly augmentthe light which 10 would naturallycome through a given aperture. hat Iclaim as new and of my invention 1. The semi-prism B, raised at. thecenter and provided with radial grooves and beveled sides 1), wherebythe radiating-surface is augmented I5 and protected from abrasion, asdescribed.

2. The central spur, c, projecting up above said face, in combinationwith projections d on thelens-t'rame, asand for thepurpose set forth.

3. Thesemi-prismB,havingitsdownwardly 20 extending tongues inclined onthebaok face,f, as and for the purpose specified.

JAMES G. PENNYOUIOK.

Witnesses:

GEO. D. WALKER, O. SEDGWIGK.

